From the Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, I.R.lran.

Abstract: (2415 Views)

Lead is known to be a potent neurotoxin that can cause seizure activity in
humans and animals. Also, epileptic type convulsion is a known complication
of hypothyroidism. This study was performed to determine the effect of
propylthiouracil (PTU)-induced hypothyroidism and chronic lead exposure on
pentylenetetrazol (PTZ)-induced kindling parameters. The test was carried out
by using male albino rats weighing 180-230 g which were divided into four
groups as follows:
Group 1: rats which received distilled water for 25 days (control group)
Group 2: rats pretreated with an orally administered lead acetate solution
(0.05%) for 25 days
Group 3: rats rendered hypothyroid with PTU solution (O.I%WIV) for 25
days and
Group 4: rats co-treated with lead acetate solution (0.05% W IV) and PTU
solution (0.1 % W IV) for 25 days.
On the 26th day of the experiment PTZ (ip, 30 mg/kg) was injected once a day
in order to induce seizure behaviors.
Kindling parameters such as seizure latency, index, stage and frequency were
evaluated. In animals, both lead acetate (0.05% WIV) and PTU (0.1 %WIV)
pretreatment caused significant alterations in kindling parameters separately.
But in animals pretreated with a combination of lead acetate and PTU, potentiation
of kindling parameters was not observed compared to groups one and two. In
conclusion, lead acetate and PTU may affect kindling parameters by different
mechanisms.